Psoriasis is a common chronic recurrent skin inflammation. The basic lesion is red papules or plaques covered with multiple layers of silvery white scales. This process is chronic.
【 Etiology and Pathogenesis 】 The exact cause of psoriasis is still unknown. At present, psoriasis is considered to be a polygenic genetic disease with the interaction of genetic factors and environmental factors, and its mechanism is an immune-mediated disease. (1) Population survey of genetic factors, family history, twins and HLA studies all support the genetic tendency of psoriasis. About 20% of psoriasis has a family history, and those with family history have an earlier onset than those without family history, and both parents have psoriasis patients who have an earlier onset age than those with normal parents. In HLA system, the expression frequency of class ⅰ antigen Aⅰ, A 13, A 28, B 13, B 17, B 37, Cw6 and class ⅱ antigen DR7 in patients with psoriasis is higher than that in normal people, and the correlation between Cw6 locus and psoriasis is the most obvious. Since 1994, six susceptibility sites of psoriasis have been identified by whole gene scanning, including 6p, 17q, 4q, 1q, 3q and 19p. But so far, no susceptibility gene or pathogenic gene of psoriasis has been found.
(II) Environmental factors Twin studies show that the proportion of identical twins suffering from psoriasis is 70%, and the consistent incidence rate is less than 100%. Therefore, it is suggested that simple genetic factors are not enough to cause psoriasis, and environmental factors play an important role in inducing psoriasis. Infection, mental stress and stress events, trauma, surgery, pregnancy, smoking and the role of some drugs are the most likely factors to promote or aggravate psoriasis.
Infection has always been considered as the main factor to promote or aggravate psoriasis. For example, there was a history of acute streptococcus infection in the throat before the onset of psoriasis guttata, and the condition often improved after antibiotic treatment.
(III) Immune factors The infiltration of lymphocytes and monocytes is obvious in the lesions of psoriasis vulgaris, especially the infiltration of T lymphocytes in the dermis is an important pathological feature of psoriasis, indicating that the immune system is involved in the occurrence and pathogenesis of the disease. It is speculated that activated T lymphocytes in skin lesions release cytokines (1L- 1, 6, 8, IFN-Y, etc. ) Stimulate the proliferation of keratinocytes and promote and maintain the course of psoriasis. An important feature of the pathophysiology of psoriasis is that the proliferation of keratinocytes in the basal layer of epidermis is accelerated, the mitotic cycle is shortened to 37.5 hours, and the epidermal renewal time is shortened to 3-4 days. Histopathologically, keratinization was incomplete and the granular layer disappeared.
【 Clinical manifestations 】 The incidence of this disease varies greatly around the world, which is related to race, geographical location, environment and other factors. The prevalence rate of natural population is 0. 1%-3%, and that of China is 0. 1.23%. It is estimated that there are 3 million people aged 15-45, with little difference between men and women. Clinically, it can be divided into four types: common type, pustule type, arthropathy type and erythroderma type, but the common type accounts for more than 99%.
(1) Psoriasis vulgaris is more common in clinic. At first, the lesion was a red maculopapule the size of mung bean, which gradually merged into a plaque with thick scales on the surface. The keratinized stratum corneum of psoriasis enters the air with a gap, and the scales are silvery white due to reflection (Figure 16-2). Scraping off layered scales is like gently scraping wax drops, so it is called wax drop phenomenon; Scrape off the scales and see a reddish translucent film, which is called film phenomenon; Gently scrape off the film, and small bleeding spots appear, which are dewdrop-shaped, which is called punctate bleeding phenomenon, that is, Auspitz's sign. This is because psoriasis is a special skin lesion, that is, the tortuous and dilated capillaries at the top of dermal papilla are scraped off. Wax drop phenomenon, film phenomenon and punctate bleeding phenomenon are the characteristics of this disease, which have diagnostic value.
Skin lesions are prone to scalp and limb extension, especially elbow and knee extension and lumbosacral region, which are widely and symmetrically distributed. In the process of disease development, the rash has many forms, such as dripping, coin-shaped, oyster shell-shaped, petal-shaped, warty and so on.
Acute drop psoriasis, also known as eruptive psoriasis, is common in young people. There is often a history of streptococcus infection in the pharynx before the onset. The onset was sudden and the rash developed rapidly. Within a few days, it can spread to the whole body in drops, which are papules and maculopapules of 0.3-0.5 cm in size. The color is flush, covered with a little scales, and the degree of itching varies. After proper treatment, it can disappear within a few weeks, and a few patients can turn into chronic diseases.
The scalp injury is a clear boundary, which extends only a few centimeters beyond the hairline of the forehead and is covered with thick scales of different sizes. Thick scales make the hair tightly connected into a bundle, but it doesn't fall off.
Facial damage may occur in the acute stage: punctate infiltrating erythema, papules or seborrheic dermatitis-like changes.
Mucosal damage is common in the glans penis and inside the foreskin, with obvious reddish patches and silvery white scales on the surface.
Nail damage is common, and the number of diseased nails can range from one to more in a few months. There are sporadic needle-like point depressions on the deck, which are uneven and dull, with horizontal grooves, longitudinal ridges, hypertrophy, nail shedding, deformity or loss.
Psoriasis has a slow course of disease, some of which occur from childhood, last for more than ten years or decades, and recur. Patients consciously have different degrees of itching, mostly in winter and light in summer. Psoriasis vulgaris can be divided into three stages according to the course of disease: 1. In the progressive stage, the rash increases and expands, with bright red color, thin scales and redness around it, and Koebner reaction is often seen. Refers to the skin with normal appearance, which is stimulated by various scratching, scratching, acupuncture, injection, strong drug application, etc., and has the same skin lesions as the primary rash. Similar phenomena can also occur in diseases such as lichen planus and lupus erythematosus.
2. In the stable period, the disease remains relatively stable, and there is basically no new rash, and the old rash gradually expands with more thick scales.
3. In the regression stage, the inflammatory infiltration of the lesion gradually subsided, the color faded and the number decreased. The center of some lesions receded annularly, leaving pigmented spots or hypopigmentation spots locally after healing. Generally speaking, the skin lesions of scalp and lower limbs tend to fade slowly from the trunk and upper limbs, and most of the exposed skin lesions naturally fade in summer.
(2) Pustular psoriasis can be divided into generalized psoriasis and localized psoriasis: 1. Generalized pustule is the most serious type in clinic, which is rare and its cause is unknown. External use of irritant drugs, infection, and sudden withdrawal of drugs during the application of glucocorticoid or immunosuppressant are all pathogenic factors. The onset is sudden and can last for several days. Relaxation high fever, accompanied by general malaise, fatigue and joint swelling, and sudden erythema. The needle is about the size of a millet. At first, it is a small piece, and then it merges into a "pus lake", which can spread to the whole body within a few weeks (Figure 16-3), and bruises, scabs and small pieces often appear at the folds. Patients with a long course of disease may be accompanied by fingertip atrophy, myasthenia, increased white blood cell count, hypocalcemia, accelerated erythrocyte sedimentation rate, and even serious systemic diseases and secondary infections. Short-term fever and pustules often recur periodically, and relieve themselves after a few days to weeks, with erythema and desquamation all over the body, which makes patients appear hypoproteinemia, poor general condition and poor prognosis.
2. The localized pustular psoriasis rash is confined to the palms and soles of the feet and distributed symmetrically. Skin lesions of palm first occurred in thenar and thenar, and then gradually spread to palm, back of hand and fingers. The metatarsal part often occurs in the middle and inside of metatarsal bone, and the rash is a group of yellowish needle-like pustules to the size of millet on symmetrical erythema, which is not easy to rupture. After about 1-2 weeks, pustules dried up, scabbed and desquamated, and groups of new blisters appeared repeatedly under the scale, so pustules, scabbed and desquamated appeared on the same skin lesion in different periods. Such repeated attacks were light and heavy and lasted for a long time. Patients are often accompanied by nail lesions, such as punctate depression, transverse groove, longitudinal ridge, nail turbidity, nail peeling, subungual abscess and so on.
(3) Arthropathic psoriasis is often accompanied by pustular psoriasis, erythrodermic psoriasis and psoriasis vulgaris, or occurs after repeated recurrence and deterioration of psoriasis. In addition to psoriasis lesions, there are symptoms of arthropathy, which are more common in men. The damage is asymmetric peripheral polyarthritis, and the distal interphalangeal joint is red, swollen, painful and deformed, often starting from the foot and gradually spreading to other joints. In severe cases, it can also involve knees, ankles, shoulders, hips and spine, with limited function and disfigurement of joints. The course of disease is chronic and progressive. The patient was accompanied by fever, anemia, hepatosplenomegaly, lymphadenopathy and other systemic symptoms. Rheumatoid factor is often negative, blood calcium is low, and Y, O and globulin are high. X-ray showed that cartilage disappeared, joint edge was eroded, and even osteolysis, joint cavity narrowing and osteoarthritis appeared.
(4) Erythrodermic psoriasis is often caused by improper treatment. For example, patients with advanced psoriasis vulgaris and acute psoriasis guttata often stop taking glucocorticoids for a long time or use drugs with strong external irritation. It can also be seen in the late stage of pustular psoriasis.
The clinical manifestation is diffuse flushing infiltration of the whole skin with a large number of chaff scales on the surface (Figure 16-4). Symptoms of psoriasis, such as silvery scales and punctate bleeding, disappear, and a normal flaky "skin island" can appear between the diffuse flush infiltration and desquamation lesions, which means that the toenails are turbid, thickened, deformed and detached, and the oral and nasal mucosa is congested and red, accompanied by chills, fever, joint pain and headache. A large number of desquamation causes protein loss, resulting in hypoproteinemia and increase of white blood cells and neutrophils in the blood. The course of disease is long and often recurs, which can cause other complications.
[histopathology]
1. The epidermis of psoriasis vulgaris changes earlier, with incomplete and hyperkeratosis. The granular layer decreased or disappeared, the spinous layer was thicker, the epidermal process decreased regularly, the end became wider and rod-shaped, the dermal papilla extended upward, and the epidermal layer above the papilla became thinner, with only 2-3 layers of spinous cells. White blood cells gather in the keratinized stratum corneum to form Munro pustules, and lymphocytes infiltrate around the superficial blood vessels of dermis.
2. The basic pathology of pustular psoriasis is the same as that of normal psoriasis. There are spongy pustules in the upper part of the spinous layer, that is, Kogoj spongy pustules. There are neutrophils in the pustules, and lymphocytes and histiocytes infiltrate in the dermis.
3. Erythrodermic psoriasis, in addition to the pathological features of psoriasis, mainly has changes such as telangiectasia and dermal edema.
[Diagnosis and differential diagnosis] Diagnostic basis of psoriasis vulgaris ① The most common parts: scalp, limb extension, knee and elbow symmetry; ② Features of rash: silvery white scales, film phenomenon and punctate bleeding; ③ Special lesions, with a chronic course of disease, mostly mild in summer and severe in winter. Recurrent attacks are easy to diagnose.
The main feature of pustular psoriasis diagnosis is that most aseptic pustules appear in batches on the basis of psoriasis vulgaris, and the condition recurs. Arthritis is often accompanied by psoriasis vulgaris or pustular psoriasis, and the severity of arthropathy symptoms is parallel to the severity of skin lesions. Erythroderma type, the whole body skin is diffuse, flushing is dry, a lot of desquamation, and there is a history of psoriasis.
It should be differentiated from the following diseases:
1. Psoriasis with seborrheic dermatitis lesions confined to the scalp should be differentiated from seborrheic dermatitis. The skin lesions of seborrheic dermatitis are flaky scales and erythema, the scales are small, greasy and yellow, there is no punctate bleeding after desquamation, the boundary of the skin lesions is unclear, the hair is sparse, sparse and falls off, and the hair is not bundled.
2. The secondary syphilis has a history of unclean sexual intercourse and chancre, and the rash is widely distributed. There are keratotic maculopapules on the palms and soles of the feet, and syphilis serum is positive.
3. Chronic simple lichen mainly occurs in limb extension and lumbosacral region. Hypertrophic psoriasis should be differentiated from this disease, which has severe itching, lichenoid lesions and almost no scales.
4. Rheumatoid arthritis psoriasis should be differentiated from this disease. The arthritis symptoms of the latter are symmetrical and progressive, and most of them invade the proximal facet joints. Rheumatoid factor positive, no psoriasis lesions and nail changes.
5. Pityriasis rosea mainly occurs in the trunk and proximal limbs, and the long axis of the rash is consistent with the direction of dermatology.
6. The onset of persistent acrodermatitis has a history of toe injury. Cluster pustules first occur in injured toes, forming submandibular pus lakes, and then spread upward, and pustules can spread all over the body.
7. Herpes pustulosis mostly occurs in pregnant women, mainly in groin, umbilical fossa, armpit, breast and other folds. It is a group of annular or multi-annular pustules with obvious systemic symptoms.
8. Erythrodermic psoriasis should be distinguished from erythrodermic psoriasis caused by other reasons. The former has a history of psoriasis, and sometimes typical residual lesions of psoriasis can be found.
[Treatment] At present, various treatment methods for psoriasis can only achieve short-term curative effect, and cannot prevent recurrence. The following points should be paid attention to in the treatment: ① Explain the patient's condition and basic knowledge, cooperate with psychotherapy, reduce mental burden and try to avoid various inducing factors. ② Psoriasis vulgaris is harmless to health, so we must not blindly pursue thorough treatment. Using drugs that can cause serious toxic and side effects, such as systemic use of corticosteroids and immunosuppressants, will worsen the condition and turn into pustular psoriasis or erythrodermic psoriasis. ③ Patients with psoriasis vulgaris complicated with acute drip, erythrodermic psoriasis and pustular psoriasis are treated with mild drugs for external use, and drugs with strong irritation are prohibited. ④ According to different causes, types and stages of illness, corresponding treatment should be given. If psoriasis is often induced by upper respiratory tract infection, antibiotics should be given and tonsillectomy should be done if necessary; Those with low cellular immune function and low white blood cell count are treated with drugs to improve fine cell immune function and increase white blood cells; Psychiatric factors induce patients to be given both sedative therapy and psychotherapy. ⑤ The localized psoriasis lesions are mainly treated with drugs, and comprehensive treatment is given when the lesions are extensive and serious.
External drug therapy
1. Glucocorticoid is the most widely used drug in treatment, and its curative effect is remarkable. Moderate glucocorticoid such as mometasone furoate cream, clozapine cream, powerful fluoxetine cream, super-effective betamethasone dipropionate, clobetasol propionate, flumethasone diacetate, and lubetaxel propionate cream or ointment are often selected.
Long-term use will cause skin atrophy, telangiectasia, folliculitis, pigmentation and other side effects. Long-term and large-scale application of potent glucocorticoid can cause systemic adverse reactions, and even induce pustular or erythrodermic silver tablets after withdrawal. 2. The common concentration of tretinoin cream is 0.025%-0. 1%, which can be combined with powerful glucocorticoid or ultraviolet (UV) treatment. Note that high concentration can cause acute or subacute dermatitis, erythema and other side effects. 0.05%-0. 1% tazarotene gel is a new generation preparation.
3. Vitamin D3 derivatives, such as calcipotriol (CPT), should be used twice a day for 6 weeks as a course of treatment, and each treatment should not exceed 40% of the body surface area, and should not be used for facial and skin wrinkles.
4. Keratin promoter psoriasis vulgaris can use tar preparation such as 5%- 10% black bean distillate, bran distillate, pine tree distillate, coal tar ointment, 5%- 10% salicylic acid ointment, 5%- 10% mercuric chloride ointment and 0.10.
5. Others such as 10% cyclosporine solution, fluorouracil preparation for treating psoriasis A, 0. 1%- 1% methotrexate containing azone for treating plaque lesions, capsaicin emulsion, 5%- 10% sulfur ointment,/kloc-0.
(2) Systematic therapy
1. immunosuppressant
(1) Methotrexate is suitable for erythrodermic psoriasis, pustular psoriasis and arthropathy psoriasis. When other treatments failed, 7.5mg per week, that is, 2.5 mg per 12 hours, three times in a row. After the symptoms are controlled, take 2.5 mg per week to consolidate the curative effect. You can also take 2.5mg/ time, 1 time/day for 5 days, take 2.5mg/ time for 2 days, 1 time/day for 5 days, and stop using for 7 days; You can also take 7.5-25mg orally once a week. Most patients take effect within 1-2 weeks, and the maintenance dose is changed after 2-3 months of treatment. Side effects include anorexia, nausea, oral mucosal ulcer, hematopoietic system and abnormal liver function, so the dosage and usage should be strictly controlled. Contraindications are hepatic and renal insufficiency, abnormal hematopoietic function, pregnancy, infectious diseases and active ulcers. Before and during medication, various laboratory tests should be carried out regularly.
(2) Methotrexate 0.25mg// time, 2-3 times/day, 6- 12 days as a course of treatment.
(3) Hydroxyurea 25-40mg/(kz? D) Take orally twice for 4-6 weeks.
(4) cyclosporine 3- 12 mg/(kz? D) Take it several days to several weeks before meals according to the illness.
(5) Tripterygium wilfordii total glycosides 10-20mg/ time, 3 times/day, or Tripterygium wilfordii tablets 3-4 times/time, 3 times/day.
2. Vitamin A, a vitamin preparation, is taken orally at 50,000 u/time, 3 times/day, or by intramuscular injection at 300,000 u/time, 1-2 times/day. Vitamin B 12 200-500 gg/d, intramuscular injection, suitable for intravenous drip of vitamin C 0. 1-0.25g/ time, 3 times /d, or 1-3 g/d with 5%- 10% glucose. Vitamin d, suitable for pustular psoriasis, 6-65438+100000 U/d for adults, taken orally in batches. αD and capsule (αD,) 0.25-0.5 gg/ time, 3 times/day, 65438 0 months as a course of treatment, and continuous administration for 2-3 months.
3. Etidic acid and Etidic acid are suitable for erythrodermic psoriasis and pustular psoriasis, and the former is 0.75 mg/(kg? D), after 1-2 weeks and 1 month, it can be maintained at 25 mg/d, and the latter is 50 mg/do. Pay attention to the side effects.
4. Antibiotics penicillin and erythromycin can be used in patients with acute guttate psoriasis and common progressive psoriasis, accompanied by tonsillitis and pharyngitis, and clindamycin can be used in generalized pustular psoriasis. Thiamphenicol and cephalosporin antibiotics can also be selected.
5. Glucocorticoid is not suitable for psoriasis vulgaris, but only for erythrodermic psoriasis, arthropathy psoriasis or generalized pustular psoriasis with systemic symptoms. When combined with immunosuppressant and tretinoin in clinic, the dosage can be reduced. Long-term use can produce a series of side effects, and the rash will recur quickly after stopping the drug, which increases the difficulty of treatment. Therefore, we should weigh the pros and cons and use them carefully.
6. Immunomodulation can be used to treat the low cellular immune function of the disease, and immunomodulators such as transfer factor, γ immunoglobulin, thymosin and vaccines can be used for treatment. Chinese medicinal materials such as Ginseng Radix, Rehmanniae Radix, Scutellariae Radix, Radix Codonopsis, Atractylodis Rhizoma, and Radix Acanthopanacis Senticosi can also be used appropriately.
7. Other sodium alginate and Agkistrodon halys antithrombotic enzyme are also effective.
8. Traditional Chinese medicine preparations can be taken orally, such as Compound Qingdai Pill, Gentiana Macrophylla Pill and Liuwei Dihuang Pill.
(3) Physical therapy
1. Psoralen long-wave ultraviolet therapy (PUVA), also known as photochemical therapy, is suitable for refractory psoriasis that cannot be controlled by other methods, and the skin lesions range from young to middle-aged. For patients with body surface area of 30%, the method is to take 8- methoxysarin 0.6 mg/kg orally, and then irradiate UVA 2-3 times a week after 2 hours.
2. Phototherapy is mainly ultraviolet therapy and Goeckerman triple therapy, that is, coal tar preparation is applied externally every day. After a few hours, you take a bath, and then you receive UVB radiation. This method has a certain effect.
There are many kinds of bath therapy, such as water, mineral spring, tar, sugar and medicated bath.
(4) Other procaine blocking therapy, peritoneal dialysis therapy, light quantum blood therapy and hyperbaric oxygen therapy also have certain curative effects.